What is the ruling on the sin incurred by my deceased father, who took "khulū rajul" (money to vacate a rented apartment) in exchange for leaving the apartment rented to him, and does the sin fall upon the one who issued the fatwa or upon him, and what must we do to lift the sin from him?

Those who are not scholars must consult specialists known for their knowledge and piety. When fatwas differ, it is not permissible to choose without a preference. If the father acted upon a weak fatwa when he could have ascertained the correct opinion, he would be sinful.

Seizing the apartment based on an unjust law is considered usurpation (ghasb), and one of the conditions for repentance is to restore grievances. The father must pay the fair rental value for the entire period the apartment was under his control, whether he utilized it or not, because the usufruct of a usurped item is guaranteed according to the majority of scholars, especially if the usurped item was prepared for utilization.

To lift the sin from the father, the right of the apartment owner must be fully restored, or a reconciliation must be reached with him to his satisfaction.